1. Technical Field
This disclosure is directed to integrated circuits, and more particularly, to power management in integrated circuits.
2. Description of the Related Art
In recent years, power management has become an increasingly important factor in the design of integrated circuits (ICs), in part due to increasing levels of integration on a single IC die. The advent of the mobile/portable electronic devices (e.g., smart phones, tablets, etc.) has further driven the demand for more power efficient ICs in order to preserve the battery life of such devices.
Responsive to the demand for more efficient power management on ICs, numerous schemes have been developed. In many ICs, various functional units implemented thereon may be clock gated or power gated. Clock gating may be defined as inhibiting a clock signal from being provided to a functional unit when that unit is idle. Similarly, power gating may be defined as inhibiting power from being provided to a functional unit when it is idle.
In some ICs, various types of hardware may be implemented to manage the power of the various functional blocks thereof. Such hardware may determine when a particular functional unit is idle, and may perform clock gating and/or power gating on that unit responsive thereto. Power management hardware may also resume providing power and/or a clock signal to a functional unit (i.e. ‘wake up’ the functional unit) in order that it may resume operation.
Software power management is another type of power management that may be implemented. Software instructions executing on an IC configured for processing instructions may determine when various functional units are idle. Responsive to determining that a functional unit is idle, instructions may be executed to cause power gating and/or clock gating. Requests for access or service by the functional unit may be detected by the software, and may be used as a queue to wake up an idle functional unit.